Vulnerability · Published May 22, 2026 · Assigned by Go
CVE-2026-39833Invoking key constraints not enforced in golang.org/x/crypto/ssh/agent
Critical 9.1
In plain English
A critical-severity security flaw in golang.org/x/crypto/ssh/agent from golang.org/x/crypto. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 41% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)9.1Critical
Exploit odds (30 days)0.5%top 59.2% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
The in-memory keyring returned by NewKeyring() silently accepted keys with the ConfirmBeforeUse constraint but never enforced it. The key would sign without any confirmation prompt, with no indication to the caller that the constraint was not in effect. NewKeyring() now returns an error when unsupported constraints are requested.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | golang-go.crypto | no fix listed | DEBIAN-CVE-2026-39833 |
| Debian:13 | golang-go.crypto | no fix listed | DEBIAN-CVE-2026-39833 |
| Debian:14 | golang-go.crypto | 1:0.52.0-1 | DEBIAN-CVE-2026-39833 |
| Go | golang.org/x/crypto | 0.52.0 | GO-2026-5005 |
| Go | golang.org/x/crypto | 0.52.0 | GHSA-jppx-rxg9-jmrx |
| Ubuntu:25.10 | golang-go.crypto | no fix listed | UBUNTU-CVE-2026-39833 |
| Ubuntu:22.04:LTS | snapd | no fix listed | UBUNTU-CVE-2026-39833 |
| Ubuntu:24.04:LTS | snapd | no fix listed | UBUNTU-CVE-2026-39833 |
| Ubuntu:25.10 | snapd | no fix listed | UBUNTU-CVE-2026-39833 |
| Ubuntu:26.04:LTS | snapd | no fix listed | UBUNTU-CVE-2026-39833 |
| Ubuntu:26.10 | snapd | no fix listed | UBUNTU-CVE-2026-39833 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| golang.org/x/crypto | golang.org/x/crypto/ssh/agent | 0 – before 0.52.0 |